docs: def popall(self, key, default=_marker):
          """Remove all occurrences of key and return the list of corresponding
          values.
  
          If key is not found, default is returned if given, otherwise
          KeyError is raised.
  
          """
          found = False
          identity = self._title(key)
          ret = []
          for i in range(len(self._impl._items)-1, -1, -1):
              item = self._impl._items[i]
              if item[0] == identity:
                  ret.append(item[2])
                  del self._impl._items[i]
                  self._impl.incr_version()
                  found = True
          if not found:
              if default is _marker:
                  raise KeyError(key)
              else:
                  return default
          else:
              ret.reverse()
              return ret